Composite Bats are made by pressing layers of resin and fiber together. The resin can be broken up in between each layer of composite by Bat Rolling. The bat is placed in between 3 rollers and pressure is added to flex the bat in order to break up the resin. As the resin breaks up the fiber is free to flex which gives the bat more of a trampoline effect. This trampoline effect equates to greater batted ball speeds. This effect can also be achieved with aluminum or alloy bats also. The metal becomes more malleable which also causes a trampoline effect and more distance to the batted ball.